Astronomers discover a rare and new kind of galaxy on the verge of death

The astrophysicists of the University of Kansas have for the first time discovered an extremely rare type of galaxy, which fundamentally changes our understanding of the death of these galaxies. At the 234th meeting of the American Astronomical Society on Thursday, Allison Kirkpatrick presented her discovery of "cold quasars", extremely bright and dying galaxies in the confines of the cosmos.

Quasars are basically supermassive mammoth black holes, surrounded by huge amounts of gas and dust, making them super bright – much brighter than a typical galaxy. They can be created when two galaxies merge and their black holes meet. For example, our galaxy, the Milky Way, is on a collision course with the neighboring galaxy of Andromeda. This event, which will take place in billions of years, will mark the end of both galaxies and the creation of a quasar.

Eventually, gas and dust will begin to fall in the center of the quasar and will be blown into space. Astronomers have hypothesized that this point is essentially the end of a galaxy's life, when it has lost the ability to form new stars and becomes "passive", but Kirkpatrick and his team discovered that a small fraction of these quasars were always training new stars.

The researchers examined the sky with X-ray and infrared telescopes and found 22 quasars 6 to 12 billion light years apart, with unusual signatures. They seemed to be at the end of their life when they were viewed optically. However, they still emit a luminous signature in the far infrared containing a lot of dust and cold gas.

At the press conference, Kirkpatrick postulated that if we could zoom in and see any of these quasars, it would be a bit like a donut. In the center of the galaxy, we would see a dead zone, where the quasar has taken away most of the gas and dust. Around the outside, we found a region in star formation still abundant in gas and dust.

"These galaxies are rare because they are in a transition phase," Kirkpatrick said in a press release. "We detected them just before the formation of stars in the galaxy was extinguished, and this transition period should be very short."

Incredibly strong winds would blow in the galaxy. This period would only last about 10 million years – a wink in the chronologies of the universe. Thus, these cold quasars are incredibly rare, and locating one is an important step in determining the maturity, life, and death of galaxies.

Is this the ultimate destiny of our own galaxy? Kirkpatrick thinks so. However, in 3 to 4 billion years, we will have other problems by then, like an expanding sun ready to engulf the Earth as a whole.